Light-operated control apparatus for a combustion engine



Aug. 26, 1969 R. ZECHNALL ETAL LIGHT-OPERATED CONTROL APPARATUS FOR ACOMBUSTION ENGINE Filed Nov. 17, 1967 3 Sheets-Sheet 1 fire/r Arrow 5yAug. 26, 1969 ZECHNALL ETAL I 3,463,134

LIGHT-OPERATED CONTROL APPARATUS FOR A COMBUSTION ENGINE Filed Nov. 17,1967 3 Sheets-Sheet 2 Aug. 26, 1969 R. ZECHNALL ETAL 3,463,134

LIGHT-OPERATED CONTROL APPARATUS FOR A COMBUSTION ENGINE Filed Nov. 17,1967 3 Sheets-Sheet :5

7'45, Arrow/[y United States Patent U.S. Cl. 123146.5 16 Claims ABSTRACTOF THE DISCLOSURE Light operated control means for the ignition circuitof a combustion engine are located spaced from the engine and itsdistributor and connected by light guiding means to the distributorwhere a rotating actuator interrupts the path of light falling into alight sensitive means.

BACKGROUND OF THE INVENTION It is known to control auxiliary operations,such as the ignition, of a combustion engine by apparatus having asource of light and a light sensitive element.

Control arrangements of this type have been successfully used for theignition means of combustion engines, and have the advantage thatmechanical contact engagement is eliminated.

The ignition means of a combustion engine serves the purpose of ignitingthe compressed air-fuel mixture, which is accomplished by an ignitingspark of the spark plug projecting into each cylinder of the engine. Inorder to initiate the igniting operation, the light emitted by a sourceand directed at a light sensitive switching element, is influenced by anactuator part driven by the engine.

In one known construction, in which the energy required for the ignitionis inductively stored in an ignition coil, the light-sensitive elementinterrupts at the moment in which ignition is desired, the circuit ofthe primary winding of the ignition coil so that a high voltage impulseis produced in the secondary winding and supplied to the spark plug.

In capacitive ignition arrangements, in which the ignition energy iscapacitively stored, the light-sensitive element effects at the momentat which ignition is desired, discharge of a previously chargedcapacitor through the primary winding of the ignition coil, so that ahigh voltage impulse is produced in the secondary winding for producingthe desired spark at the spark plug.

The use of light operated control means for initiating an ignitionoperation has the advantage that the mechanically operated distributorcontacts can be eliminated. Mechanical distributor contacts have thedisadvantage that they are frequently scorched or soiled with oil, whichresults in malfunction, and that due to friction, bouncing back, andgradual deterioration of the contact pressure, the ignition is notalways initiated at the exact moment at which it is desired.

The German Ausle-geschrift 1,120,812 discloses the use of a source oflight and of a light-sensitive switching element to replace aconventional mechanically operated distributor.

In the constructions of the prior art using light-operated control meansin the ignition circuit of a combustion engine, the source of light andthe light-sensitive electric switching element is directly mounted onthe engine, and more particularly in the distributor housing of thesame. The light-operated control means are subjected in this location tomechanical oscillations and heat, so that they rapidly deteriorate. Forexample, if an incandescent filament lamp is used as a source of light,the oscillations of the distributor will soon cause breaking of thefilament and consequent failure of the ignition. In the event that thelight-sensitive electric element is a photodiode, or a phototransistor,the heat in the region of the engine and distributor will detrimentallyinfluence the operations of these elements and of the entire electricignition apparatus, since diodes and phototransistors are greatlyinfluenced by heat.

Furthermore, in the prior art it is necessary to secure the source oflight and the light-sensitive electric element by screws or likefastening means to the distributor housing, so that the oscillations ofthe same causes loosening of the threaded connections causing changes inthe positions of the light-operated control means, which alsojeopardizes the trouble-free operation of the ignition.

SUMMARY OF THE INVENTION It is one object of the invention to provide alightoperated control means for controlling an auxiliary operation of anengine, for example, the ignition of the compressed fuel-air mixture ofa combustion engine, which is arranged and constructed in such a mannerthat the apparatus is not subjected to heat and oscillations produced bythe engine and parts of the same.

Another object of the invention is to provide a lightoperated controlmeans in which light emitted by a source is reliably guided to alight-sensitive element.

Another object of the invention is to arrange lightoperated controlmeans spaced from the distributor of a combustion engine, and to guidethe light by lightguiding means into the region of the distributor Wherean actuator cyclically opens and closes the path of the light.

With these objects in view, the present invention relates to alight-operated control apparatus for controlling auxiliary operations ofan engine, such as ignition or the injection of fuel.

One embodiment of the invention comprises a source of light and alight-sensitive means spaced from the engine, elongated light guidingmeans disposed between the source of light and the light-sensitivemeans, means for guiding light to the light-sensitive means along a pathhaving a portion in the region of the engine, and actuating means movedby the engine across said portion of the path for cyclically varying theamount of light entering the lightsensitive means, and being spaced fromthe light-operated control means a predetermined distance.

Oscillations and heat produced by the engine and the actuating means,are not transmitted to the light-operated control means since thelight-guiding means permits a substantial separation of the parts.

The term engine is used in the present application to define any engineor motor and its auxiliary devices, for example, a combustion engine anda distributor. The term light-guiding means is used in the presentapplication to define means for guiding light not only along a straightpath, but also along a curved path or around corners. For example, thelight guiding means may include preferably flexible rods consisting oflightguiding longitudinal fibers, and tubular elements having innerreflecting mirror surfaces.

In the preferred embodiments of the invention, the light-guiding meansinclude two light-guiding elements having first ends located oppositethe source of light and a light-sensitive means, respectively, andsecond confronting ends forming a gap through which a revolving portionof a rotating actuating means cyclically passes. The revolving portionmay be impermeable to light, or reflecting depending on the constructionand arrangement of the two light-guiding elements. It is alsoadvantageous to provide a lens in the gap between the light-guidingelements and to adjust the position of the lens when the position oflight-guiding elements is adjusted.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is partly a circuit diagram, andpartly an eleva vation, partially in section, illustrating oneembodiment of the invention applied to the ignition system of acombustion engine;

FIG. 2 is a diagram illustrating a modified circuit which may becombined with the embodiment of the invention shown in FIG. 1;

FIG. 3 is a fragmentary cross sectional view illustrating a part of asecond embodiment of the invention;

FIG. 4 is a fragmentary cross sectional view illustrating a part of athird embodiment of the invention;

FIG. 5 is a fragmentary plan view, partially in section, illustrating afourth embodiment of the invention; and

FIG. 6 is a fragmentary sectional view of a detail taken on line VIVI inFIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to theembodiment of FIGS. 1 and 6, a combustion engine includes a cylinderblock 2, and a distributor 1 whose housing 26 is secured by brackets 5to the cylinder block 2. The engine has two cylinders provided withgrounded spark plugs 3 and 4- which are connected with stationarycontacts 6 and 7 of the distributor. A contact arm 8 cooperates withstationary contacts 6 and 7 and is mouned on an insulator 9 carried bythe distributor shaft 10 which is driven by shaft 12 of the engine, asschematically indicated by the dash-and-dot line 11. Contact arm 8alternately engages contacts 6 and 7 during rotation of shaft 10, and isconnected by a contact spring 13 and a slide contact 14 with a lineleading to the secondary winding 15 of an ignition coil 16 which has aprimary winding 17. One pair of ends of windings 15 and 17 are grounded,and the other end of primary winding 17 is connected by a line to alight-sensitive electric switching means 18 which is also connected by aswitch 19 to the positive terminal of a battery 20 whose negativeterminal is grounded. Switch 19 also connects the positive terminal ofthe battery with one terminal of a source of light, shown to be a lamp21 whose other terminal is grounded. The light-sensitive means 18 is .aphotodiode connected in series with primary winding 17, main switch 19,and the battery 20. Instead of a photodiode, a phototransistor, andinstead of an incandescent lamp 21, a glow discharge lamp, orluminescent diode may be used.

When no light enters light-sensitive means 18, it has a high resistanceso that a small current flows through primary winding 17. When switch 19is closed, lamp 21 lights up, and if light is guided by light-guidingmeans 22 from lamp 21 into light-sensing means 18 by light guiding means22 in a manner which will be described hereinafter, the resistance oflight-sensitive means 18 drops so that a high current flows through theprimary winding. When the flow of light is interrupted, as will bedescribed hereinatfer, the resistance of light-sensitive means 18 isgreatly increased so that the flow of current through primary winding 17is reduced to an extent corresponding to an interruption so that a highvoltage impulse is induced in the secondary winding 15 of the ignitioncoil 16 which is transmitted through contacts 13, 14, contact arm 8, andone of the stationary distributor contacts 6 and 7 to either spark plug3 or spark plug 4 so that the respective spark plug produces a spark forigniting the fuel-air mixture in the respective cylinder of thecombustion engine.

.In accordance with the invention, the source of light 21 and thelight-sensitive means 18 of the above-described light-operated controlmeans are mounted on a support 23 spaced from the distributor 1 and thecylinders of the combustion engine 2, for example on the wall whichseparates the engine of a car from the drivers compartment.Consequently, neither heat nor oscillations produced by the combustionengine can detrimentally influence the sensitive elements 18 and 21.Light-guiding means 22 guide the light emitted by the source of light 21along a path having a portion in the region of the distributor 1 intothe light-sensitive means 18. In the embodiment of FIG. 1, two elongatedlight-guiding means 22 are provided. One light-guiding means ends in thewall of the distributor housing 26 and has an end 22 forming a gap 25with the confronting end 22" of the other light-guiding means 22 whichhas a straight portion merging into a U-shaped portion. The end portionof the second light-guiding element 22 is secured by clamp 27 to acarrier plate 28 which is secured to the housing 26 and has a bearingfor distributor shaft 10.

It will be seen that the light-guiding means 22 form a U-shaped path forthe light, interrupted by gap 25 in which a lens 31 is located to guidelight from end 22 into the end 22". The light-guiding means 22 may becomposed of tubular elements having mirror reflecting inner surfaces, ormay be light-guiding rods consisting of parallel longitudinallyextending light-guiding fibers.

An actuating means 24 is secured to distributor shaft 10 and rotateswith the same. Actuating means 24 has two light impermeable portions bseparated by light permeable openings a between the same. Whendistributor shaft 10 rotates together with actuating means 24, theportions b and the portions a alternately pass through gap 25 betweenthe ends 22' and 22" so that the How of light through light guidingmeans 22 is cyclically interrupted in synchronism with the engagement ofcontact arm 8 with stationary distributor contacts 6 and 7. Since thecombustion engine has two cylinders, two light impermeable portions b,and two light permeable window portions a are provided.

Whenever the flow of light is interrupted by revolving portions b, theresistance of light responsive element 18 is rapidly increased, thecurrent in the primary winding 17 is reduced, and a high voltage impulsepasses through the respective distributor contact 6 or 7 to spark plug 3or 4.

It is advantageous to provide a centrifugal governor 30 betweendistributor shaft 10 and the actuating means 24 for regulatingautomatically the timing of the ignition. The carrier plate 28 on whichthe second light-guiding element 22 is mounted is preferablyautomatically adjusted by a regulating device 29 which is connected tothe suction inlet of the combustion engine and operated by negativepressure to automatically regulate the moment of ignition. Since theadjustment of the flexible end of the light-guiding element effects adisplacement of the end 22" relative to lens 31, it is necessary toadjust the lens so that the light guided from the lamp 21 through thefirst light-guiding element 22 and passing through the end 22' of thesame, is focused by lens 31 onto the displaced end 22" of the otherlight-guiding element 22.

Lens 31 is mounted on a curved support member 32 provided with a gearsegment 32', as best seen in FIG. 6. Gear segment 32 meshes with a firstportion of a pinion 34 whose second portion meshes with a gear segment35 in the outer cylindrical surface of carrier plate 28. Pinion 34 has ashaft portion mounted in a bearing of a support plate 33 projecting fromthe wall 26 of the distributor. When the negative pressure adjustingdevice 29 displaces carrier plate 28 with the end 22 of thelight-guiding element to vary the moment at which gap 25 is crossed bythe portion b of the actuating means, the angular position of lens 31 isalso automatically adjusted so that the light passing through the end22' is reliably directed by lens 31 into the end 22", although the sameis no longer exactly aligned with the end 22'. Due to the displacementof the beam of light between lens 31 and end 22" by the negativepressure control device 29, the moment at which a portion b passes thelight path is changed, so that the light reaching the light-sensitivemeans 18 is sooner or later interrupted whereby the moment of ignition,and the timing of the same relative to the rotation of shaft 12 and ofdistributor shaft is varied.

Shielding walls 36 are provided in the distributor housing 26 to protectlens 31 and the ends of the light-guiding means 22 from dust.

In the above-described arrangement, the path of the light is interruptedby a portion b of the actuating means 24 at the moment in which ignitionis desired. It is also possible to produce an ignition spark of thespark plugs 3, 4 by blocking the path of the light for the greater partof a rotation, and to open the light path at the moment of ignition. Insuch an arrangement, the circumferential length of the portions b issubstantially greater than the circumferential length of the windowportions a, and the control circuit is modified as shown in FIG. 2. Thelightoperated control means include in addition to a photodiode 18, alsoa NPN transistor 40, a resistor 37, and a limiting resistor 38. Switch19 connects the battery 20 with lamp 21, and also connects photodiode18' through resistors 37, 38 with the positive terminal of the battery.The base collector path of transistor 40 is connected in parallel toresistor 37, and the emitter of transistor 40 is connected to theprimary winding 17. A secondary winding is connected to the stationarydistributor contacts 6, 7 and to the spark plugs, as described withreference to FIG. 1.

When switch 19 is closed, and the path of light formed by light-guidingmeans 22 and lens 31 is interrupted in the gap 25 by a light-impermeableportion of actuating means 24, the photodiode 18' has such a highresistance that the base of transistor 40 has a positive potential inrelation to the emitter so that the emitter collector path becomesconductive and a current flows through primary winding 17. In theignition moment, a window portion of the actuating means 24 passesthrough gap 25 and opens the path of the light so that the lightentering photodiode 18 reduces the resistance of the same to such anextent that the base of transistor 40 has a negative potential inrelation to the emitter. Consequently, the emitter collector path, andthereby the current flowing through primary winding 17 is interrupted sothat the high voltage impulse is induced in secondary winding 15 whichcauses an igniting spark on one of the spark plugs 3 or 4, depending onthe position of contact arm 8.

FIG. 3 illustrates modified parts of an embodiment which otherwisecorresponds to the embodiment described with reference to FIG. 1. Thesource of light 21 is farther spaced from the light-sensitive means 18,and light-guiding elements 22a have angular ends mounted in the wall 26of the distributor housing so that the end faces 22 and 22" are alignedalong a chord of the cylindrical distributor wall and of the cylindricalwall b of actuating means 24a which rotates with the distributor shaft10-. In order to permit the passage of light between the ends 22' and22', the cylindrical wall b has pairs of openings a aligned along twochords. Light can pass from end 22' and through gaps 25 into end 22"only when the openings a of a pair of openings are aligned, as shown inFIG. 3. Since the ignition system is assumed to be used with atwo-cylinder combustion engine, and the ignition impulse is to be givenby opening the path of the light between the source of light 21 and thelight-sensitive means 18, four openings a and four wall portions b areprovided. During each revolution of actuating means 24a, the path of thelight is twice opened and twice closed so that in each of the twocylinders, an igniting spark is produced at the respective spark plug 3or 4, as described with reference to FIG. 1.

A lens 31 is advantageously provided to focus and direct the light raysfrom end 22 into end 22", since the distance between the ends 22, 22" iscomparatively great.

The actuating means 24a shown in the embodiment of FIG. 3 are providedwith vanes 41 disposed close to the inner surface of the distributorwall and produce an air current during rotation of the actuating meanswith the distributor shaft 10. If the light-guiding means 22a are fiberrods, dust is blown off the end faces 22, 22". If the light-guidingelements 22a are tubular and have inner mirror reflecting surfaces, theair current enters the tubular light-guiding element and blows dust outof the same, while simultaneously cooling the lamp 21 and the lightresponsive means 18.

FIG. 4 illustrates modified parts of another embodiment which otherwisecorresponds to the embodiment shown in FIG. 1. The light-guidingelements 22b have portions symmetrically slanted at an angle a andmounted in bores of the cylindrical wall of the housing 26. Theactuating means 24b has opposite light-reflecting portions 0 which aredisposed to reflect light coming from the end 22 of the firstlight-guiding element into the end 22" of the second light-guidingelement. The light-reflecting portions may be constructed as mirrors, oras prisms, and the portions of actuating means 24b between thereflecting portions 0 may be either nonreflecting, or windows. Theignition system controlled by the embodiment of FIG. 4 is again designedfor a two-cylinder combustion engine, as described with reference toFIG. 1, and each of the reflecting portions 0 is correlated with one ofthe spark plugs 3 or 4 and assumes the operative position shown in FIG.4 for the left reflecting portion 0 at the moment at which an ignitionspark is desired while contact arm 8 engages the respective stationarydistributor contact 6 or 7, as described with reference to FIG. 1. Whenno reflecting surface is located in the gap 25, the light beam projectedfrom the end 22' of the first light-guiding element 22b cannot enter theend 22" of the second light guiding element 22b so that no light enterslight-sensitive means 18.

If the embodiment of FIG. 4 is to be modified to effect ignition at themoment in which the light entering lightsensitive means 18 isinterrupted, the portions 0 are made of a nonreflecting material, orwith a surface layer consisting of such a material, while the widecircumferential portions between the portions 0 have to be made with alight-reflecting surface.

FIG. 4 shows cleaning means in the form of a brush 42 secured to theinner surface of the distributor wall 26 and positioned so that thereflecting surfaces of the revolving portions 0 are wiped off andcleaned by brush 42 during each revolution of actuating means 24b. It isadvantageous to provide cleaning brushes, not shown, also on therotating actuating means 24b to wipe off the end face 22', 22" iflight-guiding fiber rods are used as light-guiding elements 22b. Suchbrushes may be secured to the actuating means anywhere between the lightreflecting portions 0.

FIG. 5 illustrates a modified portion of another embodiment of theinvention which otherwise corresponds to the arrangement shown inFIG. 1. The light-sensitive means 18" which must be a heat-resistanttype, is mounted on the stationary carrier plate 28 with a heatinsulating elastic dampening member 43 interposed so thatlight-sensitive means 18" is not subjected to oscillations and heatproduced by the combustion engine. The lamp 21 is mounted spaced fromthe combustion engine and distributor 1 on a supporting structureincluding a support plate 44 and a pair of springs 45 secured to theouter surface of the distributor housing wall 26. A lightguiding means220 guides the light emitted by a source of light 21 along a straightpath toward the light-sensitive means 18", and is supported in a bore ofhousing wall 25. The inner end of light-guiding means 220 forms a gapwith light-sensitive means 18 through which revolving portions ofactuating means 24, not shown in FIG. 5, pass during rotation. In FIG.5, a portion of the top wall of the distributor 1 is broken out topermit a view at the light-sensitive means 18" which is located in theinterior of the distributor housing. Support plate 44 may be made ofmetal and grounded and connected to one terminal of lamp 21. Springs 45prevent the transmission of oscillation to lamp 21, and the spacingbetween lamp 21 and the distributor can be suitably selected, since thetransmission of light to the light-sensitive means 18" from the lamp 221is asured by the lightguiding means 22c. Since no oscillations aretransmitted to the lamp 21, it can be constructed as an incandescentfilament lamp.

In a modified construction, not shown, the lamp 21 is resilientlymounted on the carrier plate 28 in the place of the light-sensitivemeans 18 of FIG. 5, and light-sensitive means 18" is mounted on aspring-supported plate, as shown for lamp 21 in the construction of FIG.5. The light-guiding means 22c assures an accurate guidance of lightemitted by lamp 21 into the light-sensitive means 18".

The ignition circuits shown in FIGS. 1 and 2 represent an inductionignition system, but it will be understood that a capacitive ignitionsystem can also be used with all embodiments of the invention. Thedischarge of a capacitor and the correlated production of an ignitingspark is obtained by means of a source of light and a light-sensitivemeans, connected by light guiding means, as explained above.

Instead of the mechanically controlled distributor including distributorarm 8 and stationary distributor contacts 6 and 7, a distributor havingswitching elements operated by light rays may be used. The actuatingmeans 24 is not necessarily mounted on the distributor shaft 10, but maybe driven directly from the shaft of the combustion engine and combinedwith the flywheel of the same, or the flywheel may be constructed withlight-permeable and light-impermeable portions and serve as actuatingmeans 24.

The precisely timed control impulse produced by the arrangement of theinvention, may be used for controlling other auxiliary operations of acombustion engine instead of the ignition. For example, the fuelinjection may be timed by impulses produced when the path of lightbetween a source of light and a light-sensitive means is opened orclosed by an actuating means in synchronism with the piston movements ofa combustion engine.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types oflight-operated control apparatus, differing from the types describedabove.

While the invention has been illustrated and described as embodied in acontrol apparatus for controlling the ignition timing of a combustionengine by means of lightoperated control means which are spaced from theengine to prevent the transmission of oscillations and heat, it is notintended to be limited to the details shown, since various modificationsand structural changes may be made without departing in any way from thespirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:

1. Light-operated control apparatus for a combustion engine, comprising,in combination, light-operated control means for controlling anauxiliary operation of said combustion engine, and including a source oflight and light-sensitive electrical means responsive to lightvariations, at least a part of said light-operated control means mountedindependently from and being spaced a predetermined distance from saidcombustion engine so that oscillations and heat produced by saidcombustion engine are not transmitted to said source of light or to saidlight-sensitive electrical means; elongated light-guiding means disposedbetween said source of light and said light-sensitive electrical meansfor conducting light by repeated total reflection, and guiding the raysof light emitted by said source of light to said light-sensitiveelectrical means along a predetermined path having a portion in theregion of said combustion engine; actuating means moved by saidcombustion engine across said portion of said path for cyclicallyvarying the amount of light entering the light-sensitive electricalmeans; and an electrical control circuit connected to saidlight-sensitive electrical means for influencing the auxiliary operationof said combustion engine when the amount of light entering saidlight-sensitive electrical means varies.

2. Control apparatus as claimed in claim 1 wherein said actuating meanscrosses said portion of said path at a point located between said sourceof light and a light entrance end of said light-guiding means.

3. Control apparatus as claimed in claim 1 wherein said actuating meanscrosses said portion of said path at a point located between the lightexit end of said lightguiding electrical means and said light-sensitivemeans.

4. Control apparatus as claimed in claim 1 wherein said light-guidingmeans include two light-guiding elements, said elements having firstends located opposite said source of light and said light-sensitiveelectrical means, respectively, and second ends forming a gap; andwherein said actuating means passes cyclically through said gap so as tobe spaced from said light-operated control means a distance determinedby the selected length of said light-guiding elements.

5. Control apparatus as claimed in claim 1 wherein said engine includesmeans for rotating said actuating means; and wherein said actuatingmeans includes at least one light permeable portion and at least onelight impermeable portion cyclically passing across said portion of saidpath for opening and closing the same for the passage of light.

6. Control apparatus as claimed in claim 1 wherein said light-guidingmeans include two light-guiding elements, said elements having firstends located opposite said source of light and said light-sensitiveelectrical means, respectively, and second ends forming a gap; andwherein said actuating means has reflecting portion which cyclicallypasses through said gap for reflecting light from one of saidlight-guiding elements into the other; and wherein said actuating meansis spaced from said lightoperated means a distance determined by theselected length of said light-guiding elements.

7. Control apparatus as claimed in claim 1 wherein said light-guidingmeans include two light-guiding elements, said elements having firstends located opposite said source of light and said light-sensitiveelectrical means, respectively, and second ends forming a gap; includingat least one lens located in said gap; and wherein said actuating meanspasses cyclically through said gap so as to be spaced from saidlight-operated means a distance determined by the selected length ofsaid lightguiding elements.

8. Control apparatus as claimed in claim 1 comprising automaticadjusting means controlled by said engine for adjusting the position ofsaid light-guiding means so that the moment at which said light-operatedcontrol means controls said auxiliary operation is adjusted.

9. Control apparatus as claimed in claim 8 comprising at least one lenslocated in said path; means for supporting said lens for movement; andwherein said automatic adjustment means also adjusts the position ofsaid lens.

10. Control apparatus as claimed in claim 1 including cleaning means forautomatically cleaning said light-guiding means and carried by saidactuating means.

11. Control apparatus as claimed in claim 1 wherein said actuating meansinclude a reflecting portion; and including stationary cleaning meansfor cleaning said refleeting portion.

12. Control apparatus as claimed in claim 1 wherein said light-guidingmeans include tubular means having a reflecting inner surface; andwherein said actuating means include means for producing an air currentdirected into said tubular means.

13. Control apparatus as claimed in claim 1 including shielding meansfor protecting at least said light-guiding means from dust.

14. Control apparatus as claimed in claim 1 wherein said enginecomprises ignition means having an electric circuit, and a rotarydistributor shaft; wherein said lightoperated control means includeswitch means located in said circuit; and wherein said actuating meansis mounted on said distributor shaft.

15. Control apparatus as claimed in claim 13 comprising a distributorhousing; and resilient means for supporting at least a part of saidlight-operated control means on said housing spaced from the same sothat heat and oscillations are not transmitted from said housing to saidpart of said light-operated control means.

16. Control apparatus as claimed in claim 1 wherein said combustionengine including a distributor and igniting means; comprising supportingmeans for said source of light and for said light-sensitive electricalmeans spaced from said distributor; wherein said light-guiding meansinclude two light-guiding elements forming a gap in the region of saiddistributor and having ends, respectively, located adjacent said sourceof light and said light-sensitive means; wherein said actuating meansrotates in timed relation with said engine and has at least onerevolving portion passing through said portion of said gap; wherein saidlight-sensitive electrical means is adapted to vary its resistance underthe influence of light; and a circuit including means connected to saidlight-responsive means, and through said distributor, to said ignitingmeans for producing a spark in the latter When the resistance f saidlight-sensitive means varies.

References Cited UNITED STATES PATENTS 2,084,267 6/1937 Hicks. 3,163,70012/1964 Williamson 8822.5

LAURENCE M. GOODRIDGE, Primary Examiner US. Cl. X.R.

